Vitamin A for preventing acute lower respiratory tract infections in children up to seven years of age

Oral vitamin A supplements to prevent acute upper respiratory tract infections in children up to seven years of age

BACKGROUND

According to global prevalence analysis studies, acute upper respiratory tract infections (URTIs) are the most common acute infectious disease in children, especially in preschool children. Acute URTIs lead to an economic burden on families and society. Vitamin A refers to the fat-soluble compound all-trans-retinol and also represents retinol and its active metabolites. Vitamin A interacts with both the innate immune system and the adaptive immune system and improves the host's defences against infections. Correlation studies show that serum retinol deficiency was associated with a higher risk of respiratory tract infections. Therefore, vitamin A supplementation may be important in preventing acute URTIs.

OBJECTIVES

To assess the effectiveness and safety of vitamin A supplements for preventing acute upper respiratory tract infections in children up to seven years of age.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, the Chinese Biomedical Literature Database, and two trial registration platforms to 8 June 2023. We also checked the reference lists of all primary studies and reviewed relevant systematic reviews and trials for additional references. We imposed no language or publication restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), which evaluated the role of vitamin A supplementation in the prevention of acute URTIs in children up to seven years of age.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included six studies (27,351 participants). Four studies were RCTs and two were cluster-RCTs. The included studies were all conducted in lower-middle-income countries (two in India, two in South Africa, one in Ecuador, and one in Haiti). Three studies included healthy children who had no vitamin A deficiency, one study included children born to HIV-infected women, one study included low-birthweight neonates, and one study included children in areas with a high local prevalence of malnutrition and xerophthalmia. In two studies, vitamin E was a co-treatment administered in addition to vitamin A. We judged the included studies to be at either a high or unclear risk of bias for random sequence generation, incomplete outcome data, and blinding. Primary outcomes Six studies reported the incidence of acute URTIs during the study period. Five studies reported the number of acute URTIs over a period of time, but there was population heterogeneity and the results were presented in different forms, therefore only three studies were meta-analysed. We are uncertain of the effect of vitamin A supplementation on the number of acute URTIs over two weeks (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.92 to 1.09; I2 = 44%; 3 studies, 22,668 participants; low-certainty evidence). Two studies reported the proportion of participants with an acute URTI. We are uncertain of the effect of vitamin A supplementation on the proportion of participants with an acute URTI (2 studies, 15,535 participants; low-certainty evidence). Only one study (116 participants) reported adverse events. No infant in either the placebo or vitamin A group was found to have feeding difficulties (failure to feed or vomiting), a bulging fontanelle, or neurological signs before or after vitamin A administration (very low-certainty evidence). Secondary outcomes Two studies (296 participants) reported the severity of subjective symptoms, presented by the mean duration of acute URTI. Vitamin A may have little to no effect on the mean duration of acute URTI (very low-certainty evidence).

AUTHORS' CONCLUSIONS

The evidence for the use of vitamin A supplementation to prevent acute URTI is uncertain, because population, dose and duration of interventions, and outcomes vary between studies. From generally very low- to low-certainty evidence, we found that there may be no benefit in the use of vitamin A supplementation to prevent acute URTI in children up to seven years of age. More RCTs are needed to strengthen the current evidence. Future research should report over longer time frames using validated tools and consistent reporting, and ensure adequate power calculations, to allow for easier synthesis of data. Finally, it is important to assess vitamin A supplementation for preschool children with vitamin A deficiency.

Oral vitamin A supplements to prevent acute upper respiratory tract infections in children up to seven years of age

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the effectiveness and safety of vitamin A supplements for preventing acute upper respiratory tract infections in children up to seven years of age.

Vitamins, microelements and the immune system: current standpoint in the fight against coronavirus disease 2019

Coronavirus disease 2019 (COVID-19) is an acute respiratory disease associated with severe systemic inflammation. The optimal status of vitamins and microelements is considered crucial for the proper functioning of the immune system and necessary for successful recovery. Most patients with respiratory distress in COVID-19 are vitamin and microelement deficient, with vitamin D and Se deficiency being the most common. Anyway, various micronutrient supplements are widely and arbitrarily used for prevention or in the treatment of COVID-19. We aimed to summarise current knowledge about molecular and physiological mechanisms of vitamins (D, A, C, B₆, B₉ and B₁₂) and microelements (Se, Zn, Cu and Fe) involved in the immune system regulation in consideration with COVID-19 pathogenesis, as well as recent findings related to their usage and effects in the prevention and treatment of COVID-19. In the early course of the pandemic, several, mainly observational, studies reported an association of some micronutrients, such as vitamin C, D and Zn, with severity reduction and survival improvement. Still, emerging randomised controlled trials showed no effect of vitamin D on hospitalisation length and no effect of vitamin C and Zn on symptom reduction. Up to date, there is evidence neither for nor against the use of micronutrients in the treatment of COVID-19. The doses that exceed the recommended for the general population and age group should not be used, except in clinical trials. Benefits of supplementation are primarily expected in populations prone to micronutrient deficiencies, who are, as well, at a higher risk of worse outcomes in COVID-19.

Homeopathic medicinal products for preventing and treating acute respiratory tract infections in children

BACKGROUND

Acute respiratory tract infections (ARTIs) are common and may lead to complications. Most children experience between three and six ARTIs annually. Although most infections are self-limiting, symptoms can be distressing. Many treatments are used to control symptoms and shorten illness duration. Most treatments have minimal benefit and may lead to adverse events. Oral homeopathic medicinal products could play a role in childhood ARTI management if evidence for their effectiveness is established. This is an update of a review first published in 2018.

OBJECTIVES

To assess the effectiveness and safety of oral homeopathic medicinal products compared with placebo or conventional therapy to prevent and treat ARTIs in children.

SEARCH METHODS

We searched CENTRAL (2022, Issue 3), including the Cochrane Acute Respiratory Infections Specialised Register, MEDLINE (1946 to 16 March 2022), Embase (2010 to 16 March 2022), CINAHL (1981 to 16 March 2022), AMED (1985 to 16 March 2022), CAMbase (searched 16 March 2022), and British Homeopathic Library (searched 26 June 2013 - no longer operating). We also searched the WHO ICTRP and ClinicalTrials.gov (16 March 2022), checked references, and contacted study authors to identify additional studies.

SELECTION CRITERIA

We included double-blind randomised controlled trials (RCTs) or double-blind cluster-RCTs comparing oral homeopathy medicinal products with identical placebo or self-selected conventional treatments to prevent or treat ARTIs in children aged 0 to 16 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

In this 2022 update, we identified three new RCTs involving 251 children, for a total of 11 included RCTs with 1813 children receiving oral homeopathic medicinal products or a control treatment (placebo or conventional treatment) for ARTIs. All studies focused on upper respiratory tract infections (URTIs), with only one study including some lower respiratory tract infections (LRTIs). Six treatment studies examined the effect on URTI recovery, and five studies investigated the effect on preventing URTIs after one to four months of treatment. Two treatment and three prevention studies involved homeopaths individualising treatment. The other studies used predetermined, non-individualised treatments. All studies involved highly diluted homeopathic medicinal products, with dilutions ranging from 1 x 10^-4 to 1 x 10^-200. We identified several limitations to the included studies, in particular methodological inconsistencies and high attrition rates, failure to conduct intention-to-treat analysis, selective reporting, and apparent protocol deviations. We assessed three studies as at high risk of bias in at least one domain, and many studies had additional domains with unclear risk of bias. Four studies received funding from homeopathy manufacturers; one study support from a non-government organisation; two studies government support; one study was co-sponsored by a university; and three studies did not report funding support. Methodological inconsistencies and significant clinical and statistical heterogeneity precluded robust quantitative meta-analysis. Only four outcomes were common to more than one study and could be combined for analysis. Odds ratios (OR) were generally small with wide confidence intervals (CI), and the contributing studies found conflicting effects, so there was little certainty that the efficacy of the intervention could be ascertained. All studies assessed as at low risk of bias showed no benefit from oral homeopathic medicinal products, whilst trials at unclear or high risk of bias reported beneficial effects. For the comparison of individualised homeopathy versus placebo or usual care for the prevention of ARTIs, two trials reported on disease severity; due to heterogeneity the data were not combined, but neither study demonstrated a clinically significant difference. We combined data from two trials for the outcome need for antibiotics (OR 0.79, 95% CI 0.35 to 1.76; low-certainty evidence). For the comparison of non-individualised homeopathy versus placebo or usual care for the prevention of ARTIs, only the outcome recurrence of ARTI was reported by more than one trial; data from three studies were combined for this outcome (OR 0.60, 95% CI 0.21 to 1.72; low-certainty evidence). For the comparison of both individualised and non-individualised homeopathy versus placebo or usual care for the treatment of ARTIs, two studies provided data on short-term cure (OR 1.31, 95% CI 0.09 to 19.54) and long-term cure (OR 1.01, 95% CI 0.10 to 9.96; very low-certainty evidence). The studies demonstrated an opposite direction of effect for both outcomes. Six studies reported on disease severity but were not combined as they used different scoring systems and scales. Three studies reported adverse events (OR 0.79, 95% CI 0.16 to 4.03; low-certainty evidence).

AUTHORS' CONCLUSIONS

Pooling of five prevention and six treatment studies did not show any consistent benefit of homeopathic medicinal products compared to placebo on ARTI recurrence or cure rates in children. We assessed the certainty of the evidence as low to very low for the majority of outcomes. We found no evidence to support the efficacy of homeopathic medicinal products for ARTIs in children. Adverse events were poorly reported, and we could not draw conclusions regarding safety.

Lessons from the health policies for children during the pandemic in Japan

It is everyone's desire to seek the sound growth of children through food education and there is a critical need for fostering an environment for this purpose. Health policies are important for this support. To the present, the Japanese society has been greatly disrupted by COVID-19 pandemic. "Stay at home", "mokusyoku (silent eating)", and mask wearing were encouraged in nationwide campaigns as public health measures to combat COVID-19. There are some papers reporting negative effects of "stay at home" and lockdowns such as weight gain, decrease in physical activities and change in eating habits. In Japan, while benefits and advantages of food education during mealtime were previously well studied, the "mokusyoku" rule may directly run counter to this food education. Moreover, there are several reports showing that nutrients might contribute to prevention of infectious diseases. Japanese children were also encouraged to wear masks all day long. The results of the clinical research, especially randomized control trials, show limited protective effect of masks. On the other hand, negative outcomes of the masks were reported in various scenes. This review focuses on these topics and arousing reconsideration for a better environment for children.

Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age

BACKGROUND

Vitamin A deficiency (VAD) is a major public health problem in low- and middle-income countries, affecting 190 million children under five years of age and leading to many adverse health consequences, including death. Based on prior evidence and a previous version of this review, the World Health Organization has continued to recommend vitamin A supplementation (VAS) for children aged 6 to 59 months. The last version of this review was published in 2017, and this is an updated version of that review.

OBJECTIVES

To assess the effects of vitamin A supplementation (VAS) for preventing morbidity and mortality in children aged six months to five years.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, six other databases, and two trials registers up to March 2021. We also checked reference lists and contacted relevant organisations and researchers to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs evaluating the effect of synthetic VAS in children aged six months to five years living in the community. We excluded studies involving children in hospital and children with disease or infection. We also excluded studies evaluating the effects of food fortification, consumption of vitamin A rich foods, or beta-carotene supplementation.

DATA COLLECTION AND ANALYSIS

For this update, two review authors independently assessed studies for inclusion resolving discrepancies by discussion. We performed meta-analyses for outcomes, including all-cause and cause-specific mortality, disease, vision, and side effects. We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

The updated search identified no new RCTs. We identified 47 studies, involving approximately 1,223,856 children. Studies were set in 19 countries: 30 (63%) in Asia, 16 of these in India; 8 (17%) in Africa; 7 (15%) in Latin America, and 2 (4%) in Australia. About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings. Most studies included equal numbers of girls and boys and lasted about one year. The mean age of the children was about 33 months. The included studies were at variable overall risk of bias; however, evidence for the primary outcome was at low risk of bias. A meta-analysis for all-cause mortality included 19 trials (1,202,382 children). At longest follow-up, there was a 12% observed reduction in the risk of all-cause mortality for VAS compared with control using a fixed-effect model (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.83 to 0.93; high-certainty evidence). Nine trials reported mortality due to diarrhoea and showed a 12% overall reduction for VAS (RR 0.88, 95% CI 0.79 to 0.98; 1,098,538 children; high-certainty evidence). There was no evidence of a difference for VAS on mortality due to measles (RR 0.88, 95% CI 0.69 to 1.11; 6 studies, 1,088,261 children; low-certainty evidence), respiratory disease (RR 0.98, 95% CI 0.86 to 1.12; 9 studies, 1,098,538 children; low-certainty evidence), and meningitis. VAS reduced the incidence of diarrhoea (RR 0.85, 95% CI 0.82 to 0.87; 15 studies, 77,946 children; low-certainty evidence), measles (RR 0.50, 95% CI 0.37 to 0.67; 6 studies, 19,566 children; moderate-certainty evidence), Bitot's spots (RR 0.42, 95% CI 0.33 to 0.53; 5 studies, 1,063,278 children; moderate-certainty evidence), night blindness (RR 0.32, 95% CI 0.21 to 0.50; 2 studies, 22,972 children; moderate-certainty evidence), and VAD (RR 0.71, 95% CI 0.65 to 0.78; 4 studies, 2262 children, moderate-certainty evidence). However, there was no evidence of a difference on incidence of respiratory disease (RR 0.99, 95% CI 0.92 to 1.06; 11 studies, 27,540 children; low-certainty evidence) or hospitalisations due to diarrhoea or pneumonia. There was an increased risk of vomiting within the first 48 hours of VAS (RR 1.97, 95% CI 1.44 to 2.69; 4 studies, 10,541 children; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

This update identified no new eligible studies and the conclusions remain the same. VAS is associated with a clinically meaningful reduction in morbidity and mortality in children. Further placebo-controlled trials of VAS in children between six months and five years of age would not change the conclusions of this review, although studies that compare different doses and delivery mechanisms are needed. In populations with documented VAD, it would be unethical to conduct placebo-controlled trials.

The role of micronutrients in the management of COIVD-19 and optimizing vaccine efficacy

Since COVID-19 was declared as a pandemic, a race between researchers has begun to deeply examine the mechanism of the virus and how to combat it. Few clinical investigations and studies have paid attention to the role of micronutrients in the disease's course and how it may affect the disease outcomes. Micronutrients have a noticeable effect on the host immune system regulation, as well as micronutrients insufficiencies where they can affect the host immune response against SARS-CoV-2 by, for example, altering the production and the function of the inflammatory cytokines such as IFN-γ, IFN-α, TNF and interleukins. Recent studies have shown that low levels of vitamin D, vitamin C, vitamin A, zinc, selenium, copper and magnesium have a great clinical impact on COVID-19 patients, where, they are linked to prolong hospital stay, increase the mortality rate and raise the complications rate related not only to the respiratory system but also to the other systems. Optimizing the need for these micronutrients will act as a productive factor by decreasing the incidence of COVID-19 infection, lowering the rate of complications, and improving the disease prognosis and outcomes. Optimal micro-nutrition supports and contributes to the efficiency of COVID-19 vaccine. The aim of this review is to highlight the role of different micronutrients in the management of COVID-19 and optimizing vaccines, and to revile the clinical effects of micronutrients deficiencies on patients with COVID-19.

Ginseng adjuvant therapy on COVID-19: A protocol for systematic review and meta-analysis

BACKGROUND

Corona virus disease 2019 (COVID-19) is spreading fast and it brings great pressure to the social economy. Many reports revealed that ginseng can develop immunity for respiratory disease, but there is no evidence to prove its effects on COVID-19. This protocol of systematic review and meta-analysis will clarify the safety and effectiveness of ginseng adjuvant therapy on COVID-19 patients.

METHODS

Different databases (Web of Science, Cochrane Library, PubMed, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, Chinese Scientific Journal Database, Wan fang Database, ClinicalTrials, World Health Organization Trials, and Chinese Clinical Trial Registry) will be retrieved to search related articles according to pre-defined inclusion and exclusion criteria. Clinical recovery time and effective rates will be assessed as the primary outcomes and any changes of patient's condition will be considered as the secondary outcomes. Subgroup analysis and sensitivity analysis will be conducted to explore sources of heterogeneity. Endnote X9.3 will be used to manage data screening. The statistical analysis will be completed by RevMan5.3 and Stata/SE 15.1 software.

RESULTS

This study will assess the effects and safety for ginseng adjuvant therapy on COVID-19 patients.

CONCLUSION

The discussion will be considered to determine whether sufficient evidence exists to prove the effects of ginseng adjuvant therapy for COVID-19 patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (ID: CRD42021277843).

Nutraceuticals in the Prevention of Viral Infections, including COVID-19, among the Pediatric Population: A Review of the Literature

In recent years, there has been a growth in scientific interest in nutraceuticals, which are those nutrients in foods that have beneficial effects on health. Nutraceuticals can be extracted, used for food supplements, or added to foods. There has long been interest in the antiviral properties of nutraceuticals, which are especially topical in the context of the ongoing COVID-19 pandemic. Therefore, the purpose of this review is to evaluate the main nutraceuticals to which antiviral roles have been attributed (either by direct action on viruses or by modulating the immune system), with a focus on the pediatric population. Furthermore, the possible applications of these substances against SARS-CoV-2 will be considered.

Association Between Serum Vitamin A Levels and Recurrent Respiratory Tract Infections in Children

To evaluate the association between serum vitamin A levels and the prevalence of recurrent respiratory tract infections (RRTIs) in children and adolescents and to provide evidence that would help decrease the prevalence of respiratory tract infections (RTIs) in children. This cross-sectional study included 8034 children and adolescents in Beijing aged 6 months to 17 years. RRTI and RTI symptoms were diagnosed according to the Clinical Concept and Management of Recurrent Respiratory Tract Infections in Children. Multivariate logistic regression models were used to evaluate the association between serum vitamin A levels and RRTIs after adjusting for potential confounders. Among the included children, 721 (8.97%) were diagnosed with vitamin A deficiency, whereas 3,073 (38.25%) were diagnosed with subclinical vitamin A deficiency. Only 28.8% (208/721) of children with vitamin A deficiency and 53.1% (1,631/3,073) of children with subclinical vitamin A deficiency had no RRTI and RTI symptoms, respectively. Compared with children with normal vitamin A levels, those with vitamin A deficiency and subclinical vitamin A deficiency had a greater risk for RRTIs, with an odds ratio (OR) of 6.924 [95% confidence interval (CI): 5.433-8.824] and 2.140 (95% CI: 1.825-2.510), respectively]. Vitamin A levels were also positively associated with RTI symptoms, with those having vitamin A deficiency and subclinical vitamin A deficiency showing an OR of 1.126 (95% CI: 0.773-1.640) and 1.216 (95% CI: 1.036-1.427), respectively. The present cross-sectional study found that low serum vitamin A levels were significantly associated with RRTI or RTI prevalence in children and adolescents.

Mega-map of systematic reviews and evidence and gap maps on the interventions to improve child well-being in low- and middle-income countries

BACKGROUND

Despite a considerable reduction in child mortality, nearly six million children under the age of five die each year. Millions more are poorly nourished and in many parts of the world, the quality of education remains poor. Children are at risk from multiple violations of their rights, including child labour, early marriage, and sexual exploitation. Research plays a crucial role in helping to close the remaining gaps in child well-being, yet the global evidence base for interventions to meet these challenges is mostly weak, scattered and often unusable by policymakers and practitioners. This mega-map encourages the generation and use of rigorous evidence on effective ways to improve child well-being for policy and programming.

OBJECTIVES

The aim of this mega-map is to identify, map and provide an overview of the existing evidence synthesis on the interventions aimed at improving child well-being in low- and middle-income countries (LMICs).

METHODS

Campbell evidence and gap maps (EGMs) are based on a review of existing mapping standards (Saran & White, 2018) which drew in particular of the approach developed by 3ie (Snilstveit, Vojtkova, Bhavsar, & Gaarder, 2013). As defined in the Campbell EGM guidance paper; "Mega-map is a map of evidence synthesis, that is, systematic reviews, and does not include primary studies" (Campbell Collaboration, 2020). The mega-map on child well-being includes studies with participants aged 0-18 years, conducted in LMICs, and published from year 2000 onwards. The search followed strict inclusion criteria for interventions and outcomes in the domains of health, education, social work and welfare, social protection, environmental health, water supply and sanitation (WASH) and governance. Critical appraisal of included systematic reviews was conducted using "A Measurement Tool to Assess Systematic Reviews"-AMSTAR-2 rating scale (Shea, et al., 2017).

RESULTS

We identified 333 systematic reviews and 23 EGMs. The number of studies being published has increased year-on-year since 2000. However, the distribution of studies across World Bank regions, intervention and outcome categories are uneven. Most systematic reviews examine interventions pertaining to traditional areas of health and education. Systematic reviews in these traditional areas are also the most funded. There is limited evidence in social work and social protection. About 69% (231) of the reviews are assessed to be of low and medium quality. There are evidence gaps with respect to key vulnerable populations, including children with disabilities and those who belong to minority groups.

CONCLUSION

Although an increasing number of systematic reviews addressing child well-being topics are being published, some clear gaps in the evidence remain in terms of quality of reviews and some interventions and outcome areas. The clear gap is the small number of reviews focusing explicitly on either equity or programmes for disadvantaged groups and those who are discriminated against.

Food policy, nutrition and nutraceuticals in the prevention and management of COVID-19: Advice for healthcare professionals

BACKGROUND

The 2019 novel coronavirus (2019-nCoV) represents an ongoing major global health crisis with a potentially unprecedented death toll and socio-economic impact in the modern era. Measures taken to reduce the rate of transmission are too unprecedented, but are deemed necessary. The extensive strain on public health services has meant that individual agency is increasingly called for. To support this, there is a need to review policy and procedure governing the food and commerce industries in particular. Additionally, it is necessary to convey a more comprehensive and nuanced understanding of relevant diet and lifestyle factors to both healthcare practitioners and the general public.

SCOPE AND APPROACH

To our knowledge, a review of possible additional measures for healthcare proffesionals, which includes the possible nutritional management COVID-19 pandemic does not yet exist.Key Findings and Conclusions: This review identifies i) changing trends in consumer awareness and purchasing patterns in response to COVID-19, and their potential future implications for the food and food-commerce industry ii) problematic elements of policy relevant to the outbreak of COVID-19, including the handling of wild-life and food-commerce, ii) newly emergent technologies in food science which represent viable and cost-effective means to reduce the risk of transmission of coronavirus, such as anti-microbial packaging, iii) important nutritional considerations with regard to coronavirus disease prevention and management, including nutrition in early infancy, and the role of select micronutrients (vitamins and minerals), phytochemicals and probiotics in conferring protection against both viral infection and pathogenicity.

The Role of Micronutrients in Support of the Immune Response against Viral Infections

Viral infections are a leading cause of morbidity and mortality worldwide, and the importance of public health practices including handwashing and vaccinations in reducing their spread is well established. Furthermore, it is well known that proper nutrition can help support optimal immune function, reducing the impact of infections. Several vitamins and trace elements play an important role in supporting the cells of the immune system, thus increasing the resistance to infections. Other nutrients, such as omega-3 fatty acids, help sustain optimal function of the immune system. The main aim of this manuscript is to discuss of the potential role of micronutrients supplementation in supporting immunity, particularly against respiratory virus infections. Literature analysis showed that in vitro and observational studies, and clinical trials, highlight the important role of vitamins A, C, and D, omega-3 fatty acids, and zinc in modulating the immune response. Supplementation with vitamins, omega 3 fatty acids and zinc appears to be a safe and low-cost way to support optimal function of the immune system, with the potential to reduce the risk and consequences of infection, including viral respiratory infections. Supplementation should be in addition to a healthy diet and fall within recommended upper safety limits set by scientific expert bodies. Therefore, implementing an optimal nutrition, with micronutrients and omega-3 fatty acids supplementation, might be a cost-effective, underestimated strategy to help reduce the burden of infectious diseases worldwide, including coronavirus disease 2019 (COVID-19).

COVID-19 Outbreak: Pathogenesis, Current Therapies, and Potentials for Future Management

At the end of 2019, a novel coronavirus (CoV) was found at the seafood market of Hubei province in Wuhan, China, and this virus was officially named coronavirus diseases 2019 (COVID-19) by World Health Organization (WHO). COVID-19 is mainly characterized by severe acute respiratory syndrome coronavirus-2 (SARS-CoV2) and creates public health concerns as well as significant threats to the economy around the world. Unfortunately, the pathogenesis of COVID-19 is unclear and there is no effective treatment of this newly life-threatening and devastating virus. Therefore, it is crucial to search for alternative methods that alleviate or inhibit the spread of COVID-19. In this review, we try to find out the etiology, epidemiology, symptoms as well as transmissions of this novel virus. We also summarize therapeutic interventions and suggest antiviral treatments, immune-enhancing candidates, general supplements, and CoV specific treatments that control replication and reproduction of SARS-CoV and Middle East respiratory syndrome coronavirus (MERS-CoV).

[Nutritional support for critically ill patients suffering from SARS-CoV-2 infection]

Patients with severe cases of COVID-19 are at high nutritional risk during their ICU stay. Prolonged immobilization associated with an exacerbated systemic inflammatory response is a major provider of ICU-acquired muscle weakness. Early enteral nutrition is recommended to gradually reach the energy target of 25 kcal/kg/day and protein target of 1.3 g/kg/day around D4. The occurrence of a Refeeding syndrome should be closely monitored. In case of feeding intolerance refractory to a prokinetic treatment, complementary or total parenteral nutrition is advised, favouring new generation mixed lipid emulsions (containing fish oil) and regular monitoring of triglyceridemia. Nutrition care of critically ill patients should be carried out with limited procedures that may pose a risk of contamination for the healthcare staff.

Food and COVID-19: Preventive/Co-therapeutic Strategies Explored by Current Clinical Trials and in Silico Studies

Foods, food ingredients, and their balanced consumption are recognized to have an important role in achieving or maintaining a state of wellbeing by acting as carriers of functional components and bioactive molecules. However, the potential contribution of foods to consumers' health has so far only been partially exploited. The rapidly evolving scenario of the coronavirus disease 2019 (COVID-19) pandemic is stimulating profound reflection on the relationships between food and the etiological agent, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, the status of knowledge regarding food as a possible defense/co-therapeutic strategy against the SARS-CoV-2 coronavirus is considered through the discussion of two main current lines of research. One line of research relates to the role of micronutrients, food components, and diets in the strengthening of the immune system through clinical trials; formulations could be developed as immune system enhancers or as co-adjuvants in therapies. The other line of research relates to investigation of the chemical interactions that specific food compounds can have with host or virus targets so as to interfere with the viral infective cycle of SARS-CoV-2. This line requires, as a first step, an in silico evaluation to discover lead compounds, which may be further developed through drug-design studies, in vitro and in vivo tests, and, finally, clinical trials to obtain therapeutic molecules. All of these promising strategies promote the role of food in preventive/co-therapeutic strategies to tackle the COVID-19 pandemic.

Difensil Immuno Reduces Recurrence and Severity of Tonsillitis in Children: A Randomized Controlled Trial

Oral supplements (OS) support the immune system in fighting upper airways infection. This study aimed to analyze the effect of Difensil Immuno (DI) on the recurrence of tonsillitis and fever in children. A multicentric randomized clinical trial was conducted. One-hundred and twenty children with chronic tonsillitis were randomly assigned to group A, B or control. Patients in group A were treated with 10 mL of DI for 90 consecutive days, patients in group B underwent treatment with 15 mL of DI for 45 consecutive days. The following data were collected at baseline (T0), T1 and T2: tonsillitis and fever episodes, tonsillar volume, blood test results. One-way ANOVA was used to analyze within and between variances. Patients in group A and B statistically improved their clinical parameters (episode of tonsillitis and fever, tonsillar volume) when compared to control group both at T1 and T2. However, T1 variances were more consistent in group A than in group B. All patients in the study groups improved their clinical outcomes. No statistically significant variances were observed in blood parameters both at T1 and T2. Our results suggest that children treated with DI had fewer episodes of tonsillitis and fever and a reduction in their tonsillar volume.

Strengthening the Immune System and Reducing Inflammation and Oxidative Stress through Diet and Nutrition: Considerations during the COVID-19 Crisis

The coronavirus-disease 2019 (COVID-19) was announced as a global pandemic by the World Health Organization. Challenges arise concerning how to optimally support the immune system in the general population, especially under self-confinement. An optimal immune response depends on an adequate diet and nutrition in order to keep infection at bay. For example, sufficient protein intake is crucial for optimal antibody production. Low micronutrient status, such as of vitamin A or zinc, has been associated with increased infection risk. Frequently, poor nutrient status is associated with inflammation and oxidative stress, which in turn can impact the immune system. Dietary constituents with especially high anti-inflammatory and antioxidant capacity include vitamin C, vitamin E, and phytochemicals such as carotenoids and polyphenols. Several of these can interact with transcription factors such as NF-kB and Nrf-2, related to anti-inflammatory and antioxidant effects, respectively. Vitamin D in particular may perturb viral cellular infection via interacting with cell entry receptors (angiotensin converting enzyme 2), ACE2. Dietary fiber, fermented by the gut microbiota into short-chain fatty acids, has also been shown to produce anti-inflammatory effects. In this review, we highlight the importance of an optimal status of relevant nutrients to effectively reduce inflammation and oxidative stress, thereby strengthening the immune system during the COVID-19 crisis.

A Review of Micronutrients and the Immune System-Working in Harmony to Reduce the Risk of Infection

Immune support by micronutrients is historically based on vitamin C deficiency and supplementation in scurvy in early times. It has since been established that the complex, integrated immune system needs multiple specific micronutrients, including vitamins A, D, C, E, B6, and B12, folate, zinc, iron, copper, and selenium, which play vital, often synergistic roles at every stage of the immune response. Adequate amounts are essential to ensure the proper function of physical barriers and immune cells; however, daily micronutrient intakes necessary to support immune function may be higher than current recommended dietary allowances. Certain populations have inadequate dietary micronutrient intakes, and situations with increased requirements (e.g., infection, stress, and pollution) further decrease stores within the body. Several micronutrients may be deficient, and even marginal deficiency may impair immunity. Although contradictory data exist, available evidence indicates that supplementation with multiple micronutrients with immune-supporting roles may modulate immune function and reduce the risk of infection. Micronutrients with the strongest evidence for immune support are vitamins C and D and zinc. Better design of human clinical studies addressing dosage and combinations of micronutrients in different populations are required to substantiate the benefits of micronutrient supplementation against infection.

Vitamin A and D intake in pregnancy, infant supplementation, and asthma development: the Norwegian Mother and Child Cohort

Background

Western diets may provide excess vitamin A, which is potentially toxic and could adversely affect respiratory health and counteract benefits from vitamin D.

Objective

The aim of this study was to examine child asthma at age 7 y in relation to maternal intake of vitamins A and D during pregnancy, infant supplementation with these vitamins, and their potential interaction.

Design

We studied 61,676 school-age children (born during 2002-2007) from the Norwegian Mother and Child Cohort with data on maternal total (food and supplement) nutrient intake in pregnancy (food-frequency questionnaire validated against biomarkers) and infant supplement use at age 6 mo (n = 54,142 children). Linkage with the Norwegian Prescription Database enabled near-complete follow-up (end of second quarter in 2015) for dispensed medications to classify asthma. We used log-binomial regression to calculate adjusted RRs (aRRs) for asthma with 95% CIs.

Results

Asthma increased according to maternal intake of total vitamin A [retinol activity equivalents (RAEs)] in the highest (≥2031 RAEs/d) compared with the lowest (≤779 RAEs/d) quintile (aRR: 1.21; 95% CI: 1.05, 1.40) and decreased for total vitamin D in the highest (≥13.6 µg/d) compared with the lowest (≤3.5 µg/d) quintile (aRR: 0.81; 95% CI: 0.67, 0.97) during pregnancy. No association was observed for maternal intake in the highest quintiles of both nutrients (aRR: 0.99; 95% CI: 0.83, 1.18) and infant supplementation with vitamin D or cod liver oil.

Conclusions

Excess vitamin A (≥2.5 times the recommended intake) during pregnancy was associated with increased risk, whereas vitamin D intake close to recommendations was associated with a reduced risk of asthma in school-age children. No association for high intakes of both nutrients suggests antagonistic effects of vitamins A and D. This trial was registered at http://www.clinicaltrials.gov as NCT03197233.

Homeopathic medicinal products for preventing and treating acute respiratory tract infections in children

BACKGROUND

Acute respiratory tract infections (ARTIs) are common and may lead to complications. Most children experience between three and six ARTIs annually. Although these infections are self-limiting, symptoms can be distressing. Many treatments are used to control symptoms and shorten illness duration. Most have minimal benefit and may lead to adverse effects. Oral homeopathic medicinal products could play a role in childhood ARTI management if evidence for effectiveness is established.

OBJECTIVES

To assess the effectiveness and safety of oral homeopathic medicinal products compared with placebo or conventional therapy to prevent and treat acute respiratory tract infections in children.

SEARCH METHODS

We searched CENTRAL (2017, Issue 11) including the Cochrane Acute Respiratory Infections Specialised Register, MEDLINE (1946 to 27 November 2017), Embase (2010 to 27 November 2017), CINAHL (1981 to 27 November 2017), AMED (1985 to December 2014), CAMbase (searched 29 March 2018), British Homeopathic Library (searched 26 June 2013 - no longer operating). We also searched the WHO ICTRP and ClinicalTrials.gov trials registers (29 March 2018), checked references, and contacted study authors to identify additional studies.

SELECTION CRITERIA

Double-blind, randomised controlled trials (RCTs) or double-blind cluster-RCTs comparing oral homeopathy medicinal products with identical placebo or self-selected conventional treatments to prevent or treat ARTIs in children aged 0 to 16 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included eight RCTs of 1562 children receiving oral homeopathic medicinal products or a control treatment (placebo or conventional treatment) for upper respiratory tract infections (URTIs). Four treatment studies examined the effect on URTI recovery, and four studies investigated the effect on preventing URTIs after one to three months of treatment, followed up for the remainder of the year. Two treatment and two prevention studies involved homeopaths individualising treatment. The other studies used predetermined, non-individualised treatments. All studies involved highly diluted homeopathic medicinal products.We found several limitations to the included studies, in particular methodological inconsistencies and high attrition rates, failure to conduct intention-to-treat analysis, selective reporting, and apparent protocol deviations. We assessed three studies as at high risk of bias in at least one domain, and many had additional domains with unclear risk of bias. Three studies received funding from homeopathy manufacturers; one support from a non-government organisation; two government support; one was cosponsored by a university; and one did not report funding support.Methodological inconsistencies and significant clinical and statistical heterogeneity precluded robust quantitative meta-analysis. Only four outcomes were common to more than one study and could be combined for analysis. Odds ratios (OR) were generally small with wide confidence intervals (CI), and the contributing studies found conflicting effects, so there was little certainty that the efficacy of the intervention could be ascertained. All studies assessed as at low risk of bias showed no benefit from oral homeopathic medicinal products; trials at uncertain and high risk of bias reported beneficial effects.We found low-quality evidence that non-individualised homeopathic medicinal products confer little preventive effect on ARTIs (OR 1.14, 95% CI 0.83 to 1.57). We found low-quality evidence from two individualised prevention studies that homeopathy has little impact on the need for antibiotic usage (N = 369) (OR 0.79, 95% CI 0.35 to 1.76). We also assessed adverse events, hospitalisation rates and length of stay, days off school (or work for parents), and quality of life, but were not able to pool data from any of these secondary outcomes.There is insufficient evidence from two pooled individualised treatment studies (N = 155) to determine the effect of homeopathy on short-term cure (OR 1.31 favouring placebo, 95% CI 0.09 to 19.54; very low-quality evidence) and long-term cure rates (OR 0.99, 95% CI 0.10 to 9.67; very low-quality evidence). Adverse events were reported inconsistently; however, serious events were not reported. One study found an increase in the occurrence of non-severe adverse events in the treatment group.

AUTHORS' CONCLUSIONS

Pooling of two prevention and two treatment studies did not show any benefit of homeopathic medicinal products compared to placebo on ARTI recurrence or cure rates in children. We found no evidence to support the efficacy of homeopathic medicinal products for ARTIs in children. Adverse events were poorly reported, so conclusions about safety could not be drawn.

Homeopathic medicinal products for preventing and treating acute respiratory tract infections in children

BACKGROUND

Acute respiratory tract infections (ARTIs) are common and may lead to complications. Most children experience between three and six ARTIs each year. Although these infections are self limiting, the symptoms can be distressing. Many treatments are used to control symptoms and shorten the duration of illness. They often have minimal benefit and may lead to adverse effects. Oral homeopathic medicinal products could play a role in the treatment of ARTIs for children if evidence for effectiveness is established.

OBJECTIVES

To assess the effectiveness and safety of oral homeopathic medicinal products compared with placebo or conventional therapy to prevent and treat acute respiratory tract infections in children.

SEARCH METHODS

We searched CENTRAL (2017, Issue 11), which contains the Cochrane Acute Respiratory Infections Specialised Register, MEDLINE (1946 to 27 November 2017), Embase (2010 to 27 November 2017), CINAHL (1981 to 27 November 2017), AMED (1985 to December 2014), CAMbase (searched 29 March 2018), British Homeopathic Library (searched 26 June 2013 - no longer operating). We also searched the WHO ICTRP and ClinicalTrials.gov trials registers (29 March 2018), checked references, and contacted study authors to identify additional studies.

SELECTION CRITERIA

Double-blind, randomised controlled trials (RCTs) or double-blind cluster-RCTs comparing oral homeopathy medicinal products with identical placebo or self selected conventional treatments to prevent or treat ARTIs in children aged 0 to 16 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included eight RCTs of 1562 children receiving oral homeopathic medicinal products or a control treatment (placebo or conventional treatment) for upper respiratory tract infections (URTIs). Four treatment studies examined the effect on recovery from URTIs, and four studies investigated the effect on preventing URTIs after one to three months of treatment and followed up for the remainder of the year. Two treatment and two prevention studies involved homeopaths individualising treatment for children. The other studies used predetermined, non-individualised treatments. All studies involved highly diluted homeopathic medicinal products.We found several key limitations to the included studies, in particular methodological inconsistencies and high attrition rates, failure to conduct intention-to-treat analysis, selective reporting, and apparent protocol deviations. We assessed three studies as at high risk of bias in at least one domain, and many had additional domains with unclear risk of bias. Three studies received funding from homeopathy manufacturers; one reported support from a non-government organisation; two received government support; one was cosponsored by a university; and one did not report funding support.Methodological inconsistencies and significant clinical and statistical heterogeneity precluded robust quantitative meta-analysis. Only four outcomes were common to more than one study and could be combined for analysis. Odds ratios (OR) were generally small with wide confidence intervals (CI), and the contributing studies found conflicting effects, so there was little certainty that the efficacy of the intervention could be ascertained. All studies assessed as at low risk of bias showed no benefit from oral homeopathic medicinal products; trials at uncertain and high risk of bias reported beneficial effects.We found low-quality evidence that non-individualised homeopathic medicinal products confer little preventive effect on ARTIs (OR 1.14, 95% CI 0.83 to 1.57). We found low-quality evidence from two individualised prevention studies that homeopathy has little impact on the need for antibiotic usage (N = 369) (OR 0.79, 95% CI 0.35 to 1.76). We also assessed adverse events, hospitalisation rates and length of stay, days off school (or work for parents), and quality of life, but were not able to pool data from any of these secondary outcomes.There is insufficient evidence from two pooled individualised treatment studies (N = 155) to determine the effect of homeopathy on short-term cure (OR 1.31, 95% CI 0.09 to 19.54; very low-quality evidence) and long-term cure rates (OR 1.01, 95% CI 0.10 to 9.96; very low-quality evidence). Adverse events were reported inconsistently; however, serious events were not reported. One study found an increase in the occurrence of non-severe adverse events in the treatment group.

AUTHORS' CONCLUSIONS

Pooling of two prevention and two treatment studies did not show any benefit of homeopathic medicinal products compared to placebo on recurrence of ARTI or cure rates in children. We found no evidence to support the efficacy of homeopathic medicinal products for ARTIs in children. Adverse events were poorly reported, so conclusions about safety could not be drawn.

Vitamin A supplementation for preventing morbidity and mortality in children from six months to five years of age

BACKGROUND

Vitamin A deficiency (VAD) is a major public health problem in low- and middle-income countries, affecting 190 million children under five years of age and leading to many adverse health consequences, including death. Based on prior evidence and a previous version of this review, the World Health Organization has continued to recommend vitamin A supplementation for children aged 6 to 59 months. There are new data available from recently published randomised trials since the previous publication of this review in 2010, and this update incorporates this information and reviews the evidence.

OBJECTIVES

To assess the effects of vitamin A supplementation (VAS) for preventing morbidity and mortality in children aged six months to five years.

SEARCH METHODS

In March 2016 we searched CENTRAL, Ovid MEDLINE, Embase, six other databases, and two trials registers. We also checked reference lists and contacted relevant organisations and researchers to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-RCTs evaluating the effect of synthetic VAS in children aged six months to five years living in the community. We excluded studies involving children in hospital and children with disease or infection. We also excluded studies evaluating the effects of food fortification, consumption of vitamin A rich foods, or beta-carotene supplementation.

DATA COLLECTION AND ANALYSIS

For this update, two reviewers independently assessed studies for inclusion and abstracted data, resolving discrepancies by discussion. We performed meta-analyses for outcomes, including all-cause and cause-specific mortality, disease, vision, and side effects. We used the GRADE approach to assess the quality of the evidence.

MAIN RESULTS

We identified 47 studies (4 of which are new to this review), involving approximately 1,223,856 children. Studies took place in 19 countries: 30 (63%) in Asia, 16 of these in India; 8 (17%) in Africa; 7 (15%) in Latin America, and 2 (4%) in Australia. About one-third of the studies were in urban/periurban settings, and half were in rural settings; the remaining studies did not clearly report settings. Most of the studies included equal numbers of girls and boys and lasted about a year. The included studies were at variable overall risk of bias; however, evidence for the primary outcome was at low risk of bias. A meta-analysis for all-cause mortality included 19 trials (1,202,382 children). At longest follow-up, there was a 12% observed reduction in the risk of all-cause mortality for vitamin A compared with control using a fixed-effect model (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.83 to 0.93; high-quality evidence). This result was sensitive to choice of model, and a random-effects meta-analysis showed a different summary estimate (24% reduction: RR 0.76, 95% CI 0.66 to 0.88); however, the confidence intervals overlapped with that of the fixed-effect model. Nine trials reported mortality due to diarrhoea and showed a 12% overall reduction for VAS (RR 0.88, 95% CI 0.79 to 0.98; 1,098,538 participants; high-quality evidence). There was no significant effect for VAS on mortality due to measles, respiratory disease, and meningitis. VAS reduced incidence of diarrhoea (RR 0.85, 95% CI 0.82 to 0.87; 15 studies; 77,946 participants; low-quality evidence) and measles (RR 0.50, 95% CI 0.37 to 0.67; 6 studies; 19,566 participants; moderate-quality evidence). However, there was no significant effect on incidence of respiratory disease or hospitalisations due to diarrhoea or pneumonia. There was an increased risk of vomiting within the first 48 hours of VAS (RR 1.97, 95% CI 1.44 to 2.69; 4 studies; 10,541 participants; moderate-quality evidence).

AUTHORS' CONCLUSIONS

Vitamin A supplementation is associated with a clinically meaningful reduction in morbidity and mortality in children. Therefore, we suggest maintaining the policy of universal supplementation for children under five years of age in populations at risk of VAD. Further placebo-controlled trials of VAS in children between six months and five years of age would not change the conclusions of this review, although studies that compare different doses and delivery mechanisms are needed. In populations with documented vitamin A deficiency, it would be unethical to conduct placebo-controlled trials.

Essential interventions for child health

Child health is a growing concern at the global level, as infectious diseases and preventable conditions claim hundreds of lives of children under the age of five in low-income countries. Approximately 7.6 million children under five years of age died in 2011, calculating to about 19 000 children each day and almost 800 every hour. About 80 percent of the world’s under-five deaths in 2011 occurred in only 25 countries, and about half in only five countries: India, Nigeria, Democratic Republic of the Congo, Pakistan and China. The implications and burden of such statistics are huge and will have dire consequences if they are not corrected promptly. This paper reviews essential interventions for improving child health, which if implemented properly and according to guidelines have been found to improve child health outcomes, as well as reduce morbidity and mortality rates. It also includes caregivers and delivery strategies for each intervention. Interventions that have been associated with a decrease in mortality and disease rates include exclusive breastfeeding, complementary feeding strategies, routine immunizations and vaccinations for children, preventative zinc supplementation in children, and vitamin A supplementation in vitamin A deficient populations.

Essential interventions: implementation strategies and proposed packages of care

In an effort to accelerate progress towards achieving Millennium Development Goal (MDG) 4 and 5, provision of essential reproductive, maternal, newborn and child health (RMNCH) interventions is being considered. Not only should a state-of-the-art approach be taken for services delivered to the mother, neonate and to the child, but services must also be deployed across the household to hospital continuum of care approach and in the form of packages. The paper proposed several packages for improved maternal, newborn and child health that can be delivered across RMNCH continuum of care. These packages include: supportive care package for women to promote awareness related to healthy pre-pregnancy and pregnancy interventions; nutritional support package for mother to improve supplementation of essential nutrients and micronutrients; antenatal care package to detect, treat and manage infectious and noninfectious diseases and promote immunization; high risk care package to manage preeclampsia and eclampsia in pregnancy; childbirth package to promote support during labor and importance of skilled birth attendance during labor; essential newborn care package to support healthy newborn care practices; and child health care package to prevent and manage infections. This paper further discussed the implementation strategies for employing these interventions at scale.

Prebiotics in healthy infants and children for prevention of acute infectious diseases: a systematic review and meta-analysis

Prebiotics, defined as nondigestible dietary ingredients resistant to gastric acidity and fermented by the intestinal flora, are used to positively influence the composition of intestinal flora, thereby promoting health benefits. The objective of this systematic review was to assess the efficacy of prebiotics in the prevention of acute infectious diseases in children. A systematic literature search was conducted using the Ovid Medline, Scopus, Web of Science, and Cochrane Library's Central databases. Finally, five randomized controlled trials, all of them investigating infants and children 0-24 months of age, were included in the review. Pooled estimates from three studies revealed a statistically significant decrease in the number of infectious episodes requiring antibiotic therapy in the prebiotic group as compared with the placebo group (rate ratio 0.68; 95% confidence interval 0.61-0.77). Studies available indicate that prebiotics may also be effective in decreasing the rate of overall infections in infants and children 0-24 months of age. Further studies in the age group 3-18 years are required to determine whether prebiotics can be considered for the prevention of acute infectious diseases in the older pediatric population.

Vitamin A deficiency is associated with gastrointestinal and respiratory morbidity in school-age children

Infection is an important cause of morbidity throughout childhood. Poor micronutrient status is a risk factor for infection-related morbidity in young children, but it is not clear whether these associations persist during school-age years. We examined the relation between blood concentrations of micronutrient status biomarkers and risk of gastrointestinal and respiratory morbidity in a prospective study of 2774 children aged 5-12 y from public schools in Bogotá, Colombia. Retinol, zinc, ferritin, mean corpuscular volume, hemoglobin, erythrocyte folate, and vitamin B-12 concentrations were measured in blood at enrollment into the cohort. Children were followed for 1 academic year for incidence of morbidity, including diarrhea with vomiting, cough with fever, earache or ear discharge with fever, and doctor visits. Compared with adequate vitamin A status (≥30.0 μg/dL), vitamin A deficiency (<10.0 μg/dL) was associated with increased risk of diarrhea with vomiting [unadjusted incidence rate ratio (IRR): 2.17; 95% CI: 0.95, 4.96; P-trend = 0.03] and cough with fever (unadjusted IRR: 2.36; 95% CI: 1.30, 4.31; P-trend = 0.05). After adjustment for several sociodemographic characteristics and hemoglobin concentrations, every 10 μg/dL plasma retinol was associated with 18% fewer days of diarrhea with vomiting (P < 0.001), 10% fewer days of cough with fever (P < 0.001), and 6% fewer doctor visits (P = 0.01). Every 1 g/dL of hemoglobin was related to 17% fewer days with ear infection symptoms (P < 0.001) and 5% fewer doctor visits (P = 0.009) after controlling for sociodemographic factors and retinol concentrations. Zinc, ferritin, mean corpuscular volume, erythrocyte folate, and vitamin B-12 status were not associated with morbidity or doctor visits. Vitamin A and hemoglobin concentrations were inversely related to rates of morbidity in school-age children. Whether vitamin A supplementation reduces the risk or severity of infection in children over 5 y of age needs to be determined.

The role of The Cochrane Collaboration in support of the WHO Nutrition Guidelines

This article describes the background and contribution of The Cochrane Collaboration to the WHO Nutrition Guidelines program. Systematic reviews, augmented by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology for assessing the quality of a body of evidence, form the evidence basis for WHO guidelines. Our shared experience of working together has highlighted a number of issues that are challenging, such as decisions made about selecting appropriate questions for evidence synthesis and the nature of study types that are included, in particular the decision on whether or not to extend a search beyond randomized studies. Although the skills and experience required for evidence synthesis are different from those needed to determine recommendations for policy and practice, our experience suggests that some engagement between the two groups is mutually beneficial. Finally, our experience highlights the recognition that evidence of effectiveness is essential but by no means sufficient to guide decisions on recommendations. Programmatic and implementation considerations are important to guide decision making and the evidence basis for this may be limited; therefore, it is essential that groups involved in delivering interventions to populations are also engaged in the guidelines process.

In vitro inhibition of mumps virus by retinoids

BACKGROUND

Mumps virus (MuV) is a highly infectious paramyxovirus closely related to measles virus (MeV). Despite the availability of a mumps vaccine, outbreaks continue to occur and no treatment options are available. Vitamin A and other naturally occurring retinoids inhibit the replication of MeV in vitro.

METHODS

Anti-viral effects of retinoids were observed in cell culture using the myelomonocytic U937, NB4/R4, and Huh7/7.5 cells. Observations of anti-viral effect were quantified using TCID50 analysis. Molecular properties of the antiviral effect were analysed using quantitative RT-PCR and western blot.

RESULTS

The current work demonstrates that retinoids inhibit MuV in vitro due to up-regulation of type I interferon (IFN) and IFN stimulated genes. This effect is mediated by nuclear retinoid receptor signalling and RIG-I is required. The antiviral retinoid-induced state makes cells less permissive to viral replication from subsequent challenge with either MuV or MeV for less than 12 hours.

CONCLUSIONS

These results demonstrate that retinoids inhibit MuV replication in uninfected bystander cells through a retinoid inducible gene I (RIG-I), retinoic acid receptor (RAR) and IFN dependent manner making them refractory to subsequent rounds of viral replication. These observations raise the possibility that pharmacological doses of retinoids might have clinical benefit in MuV infection.

Role of Fat-Soluble Vitamins A and D in the Pathogenesis of Influenza: A New Perspective

Reduced exposure to solar radiation, leading to a deficiency of vitamin D and hence impaired innate immunity, has been suggested as a trigger for influenza viral replication and as an explanation of seasonal influenza. Although this hypothesis accounts for many unexplained facts about the epidemiology of influenza, gaps remain in understanding the pathogenesis and manifestations of the disease. Several observations suggest a role for vitamin A compounds (retinoids) in the disease. This paper presents a new model of the etiopathogenesis of influenza, suggesting that host resistance and susceptibility depend importantly on the ratio of vitamin D to vitamin A activity. Retinoid concentrations within normal physiological limits appear to inhibit influenza pathogenesis whereas higher background concentrations (i.e., very low vitamin D : A ratios) increase the risk of severe complications of the disease. There is also evidence that influenza-induced or preexisting liver disease, diabetes, and obesity worsen the severity of infection, possibly via liver dysfunction and alterations in retinoid metabolism. The model could be tested by determining the presence of retinoids in the secretions of patients with influenza and by studies of retinoid profiles in patients and controls. Potential strategies for prevention and treatment are discussed.

Reducing uncertainty in managing respiratory tract infections in primary care

Respiratory tract infections (RTIs) remain the commonest reason for acute consultations in primary care in resource-rich countries. Their spectrum and severity has changed from the time that antibiotics were discovered, largely from improvements in the socioeconomic determinants of health as well as vaccination. The benefits from antibiotic treatment for common RTIs have been shown to be largely overstated. Nevertheless, serious infections do occur. Currently, no clinical features or diagnostic test, alone or in combination, adequately determine diagnosis, aetiology, prognosis, or response to treatment. This narrative review focuses on emerging evidence aimed at helping clinicians reduce and manage uncertainty in treating RTIs. Consultation rate and prescribing rate trends are described, evidence of increasing rates of complications are discussed, and studies and the association with antibiotic prescribing are examined. Methods of improving diagnosis and identifying those patients who are at increased risk of complications from RTIs, using clinical scoring systems, biomarkers, and point of care tests are also discussed. The evidence for alternative management options for RTIs are summarised and the methods for changing public and clinicians' beliefs about antibiotics, including ways in which we can improve clinician-patient communication skills for management of RTIs, are described.

Vitamin A supplementation for preventing morbidity and mortality in children from 6 months to 5 years of age

BACKGROUND

Vitamin A deficiency (VAD) is a major public health problem in low and middle income countries affecting 190 million children under 5. VAD can lead to many adverse health consequences, including death.

OBJECTIVES

To evaluate the effect of vitamin A supplementation (VAS) for preventing morbidity and mortality in children aged 6 months to 5 years.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2010 Issue 2),  MEDLINE (1950 to April Week 2 2010), EMBASE (1980 to 2010 Week 16), Global Health (1973 to March 2010), Latin American and Caribbean Health Sciences (LILACS), metaRegister of Controlled Trials and African Index Medicus (27 April 2010).

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster RCTs evaluating the effect of synthetic VAS in children aged 6 months to 5 years living in the community. We excluded studies concerned with children in hospital and children with disease or infection. We excluded studies evaluating the effects of food fortification, consumption of vitamin A rich foods or beta-carotene supplementation.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion. Data were double abstracted and discrepancies were resolved by discussion. Meta-analyses were performed for outcomes including all-cause and cause-specific mortality, disease, vision, and side-effects.

MAIN RESULTS

43 trials involving 215,633 children were included. A meta-analysis for all-cause mortality included 17 trials comprising 194,795 children with 3536 deaths in both groups. At follow-up, there was a 24% observed reduction in the risk of all-cause mortality for Vitamin A compared with Control (Relative risk (RR) = 0.76 [95% confidence interval (CI) 0.69, 0.83]). Seven trials reported diarrhoea mortality and a 28% overall reduction for VAS (RR = 0.72 [0.57, 0.91]). There was no significant effect of VAS on cause specific mortality of measles, respiratory disease and meningitis. VAS reduced incidence of diarrhoea (RR = 0.85 [0.82, 0.87]) and measles morbidity (RR = 0.50 [0.37, 0.67]); however, there was no significant effect on incidence of respiratory disease or hospitalisations due to diarrhoea or pneumonia. There was an increased risk of vomiting within the first 48 hours of VAS (RR = 2.75 [1.81, 4.19]).

AUTHORS' CONCLUSIONS

VAS is effective in reducing all-cause mortality by about 24% compared to no treatment. In our opinion, given the evidence that VAS causes considerable reduction in child mortality, further placebo-controlled trials of VAS in children between 6 months and 5 years of age are not required. There is a need for further studies comparing different doses and delivery mechanisms (for example, fortification).

Both high and low serum vitamin D concentrations are associated with tuberculosis: a case-control study in Greenland

Vitamin D deficiency has been associated with increased risk of tuberculosis (TB). Changes from a traditional to a Westernised diet among Greenlanders have resulted in reduced serum vitamin D, leading to considerations of whether preventive vitamin D supplementation should be introduced. The association between vitamin D status and TB was examined to assess the feasibility of vitamin D supplementation in Greenland. This was examined in a case-control study involving seventy-two matched pairs of TB patients (cases) and controls aged 8-74 years. Cases were diagnosed with TB during 2004-6 based on clinical findings in combination with either (1) positive Mycobacterium tuberculosis culture, (2) characteristic X-ray abnormalities together with a positive tuberculin skin test or a positive interferon-γ release assay or (3) characteristic histology. Controls were individually matched on age ( ± 5 years), sex and district. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured and OR of TB were the outcome. Compared with individuals with 25(OH)D concentrations between 75 and 140 nmol/l, individuals with concentrations < 75 nmol/l (OR 6.5; 95% CI 1.8, 23.5) or > 140 nmol/l (OR 6.5; 95% CI 1.9, 22.2) had higher risks of active TB (P = 0.003; adjustment for alcohol and ethnicity). Supplementing individuals with low vitamin D to normalise serum 25(OH)D concentrations was estimated to result in a 29% reduction in the number of TB cases. The study indicated that vitamin D supplementation may be beneficial to individuals with insufficient vitamin D concentrations but may increase the risk of TB among individuals with normal or high concentrations.

Micronutrient fortification to improve growth and health of maternally HIV-unexposed and exposed Zambian infants: a randomised controlled trial

Background

The period of complementary feeding, starting around 6 months of age, is a time of high risk for growth faltering and morbidity. Low micronutrient density of locally available foods is a common problem in low income countries. Children of HIV-infected women are especially vulnerable. Although antiretroviral prophylaxis can reduce breast milk HIV transmission in early infancy, there are no clear feeding guidelines for after 6 months. There is a need for acceptable, feasible, affordable, sustainable and safe (AFASS by WHO terminology) foods for both HIV-exposed and unexposed children after 6 months of age.

Methods and Findings

We conducted in Lusaka, Zambia, a randomised double-blind trial of two locally made infant foods: porridges made of flour composed of maize, beans, bambaranuts and groundnuts. One flour contained a basal and the other a rich level of micronutrient fortification. Infants (n = 743) aged 6 months were randomised to receive either regime for 12 months. The primary outcome was stunting (length-for-age Z<−2) at age 18 months. No significant differences were seen between trial arms overall in proportion stunted at 18 months (adjusted odds ratio 0.87; 95% CI 0.50, 1.53; P = 0.63), mean length-for-age Z score, or rate of hospital referral or death. Among children of HIV-infected mothers who breastfed <6 months (53% of HIV-infected mothers), the richly-fortified porridge increased length-for-age and reduced stunting (adjusted odds ratio 0.17; 95% CI 0.04, 0.84; P = 0.03). Rich fortification improved iron status at 18 months as measured by hemoglobin, ferritin and serum transferrin receptors.

Conclusions

In the whole study population, the rich micronutrient fortification did not reduce stunting or hospital referral but did improve iron status and reduce anemia. Importantly, in the infants of HIV-infected mothers who stopped breastfeeding before 6 months, the rich fortification improved linear growth. Provision of such fortified foods may benefit health of these high risk infants.

Trial registration

Controlled-Trials.com ISRCTN37460449

Perinatal nutrition and immunity to infection

Epidemiological data provide strong evidence for a relationship between undernutrition and life-threatening infection in infants and children. However, the mechanisms that underlie this relationship are poorly understood. Through foetal life, infancy and childhood, the immune system undergoes a process of functional maturation. The adequacy of this process is dependent on environmental factors, and there is accumulating evidence of the impact of pre- and post-natal nutrition in this regard. This review outlines the impact of nutrition during foetal and infant development on the capacity to mount immune responses to infection. It provides an overview of the epidemiologic evidence for such a role and discusses the possible mechanisms involved.

Evidence for perinatal and child health care guidelines in crisis settings: can Cochrane help?

BACKGROUND

It is important that healthcare provided in crisis settings is based on the best available research evidence. We reviewed guidelines for child and perinatal health care in crisis situations to determine whether they were based on research evidence, whether Cochrane systematic reviews were available in the clinical areas addressed by these guidelines and whether summaries of these reviews were provided in Evidence Aid.

METHODS

Broad internet searches were undertaken to identify relevant guidelines. Guidelines were appraised using AGREE and the clinical areas that were relevant to perinatal or child health were extracted. We searched The Cochrane Database of Systematic Reviews to identify potentially relevant reviews. For each review we determined how many trials were included, and how many were conducted in resource-limited settings.

RESULTS

Six guidelines met selection criteria. None of the included guidelines were clearly based on research evidence. 198 Cochrane reviews were potentially relevant to the guidelines. These reviews predominantly addressed nutrient supplementation, breastfeeding, malaria, maternal hypertension, premature labour and prevention of HIV transmission. Most reviews included studies from developing settings. However for large portions of the guidelines, particularly health services delivery, there were no relevant reviews. Only 18 (9.1%) reviews have summaries in Evidence Aid.

CONCLUSIONS

We did not identify any evidence-based guidelines for perinatal and child health care in disaster settings. We found many Cochrane reviews that could contribute to the evidence-base supporting future guidelines. However there are important issues to be addressed in terms of the relevance of the available reviews and increasing the number of reviews addressing health care delivery.

Vitamin A for preventing acute lower respiratory tract infections in children up to seven years of age

BACKGROUND

Vitamin A supplements are effective for preventing diarrhoea. There are theoretical reasons it might also be effective for acute lower respiratory tract infections (LRTIs), also very common in children, especially in low income countries.

OBJECTIVES

To assess the effectiveness and safety of vitamin A for preventing acute LRTIs in children up to seven years of age.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2); MEDLINE (1966 to July 2007); EMBASE (1974 to July 2007); and the Chinese Biomedicine Database (CBM) (1976 to July 2007).

SELECTION CRITERIA

Randomised controlled trials (RCTs) that assessed the effectiveness of vitamin A in the prevention of acute LRTI in children up to seven years of age.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data and assessed trial quality. Study authors were contacted for additional information.

MAIN RESULTS

Most studies found no significant effect of vitamin A on the incidence of acute LRTI, or prevalence of symptoms of acute LRTI. Vitamin A caused an increased incidence of acute LRTI in one study; an increase in cough and fever; and increased symptoms of cough and rapid breathing in two others. Three reported no differences and no protective effect of vitamin A. Two studies reported that vitamin A significantly reduced the incidence of acute LRTI with children with poor nutritional status or weight, but increased it in normal children.

AUTHORS' CONCLUSIONS

This unexpected result is outside our current understanding of the use of vitamin A for preventing acute LRTIs. Accordingly, vitamin A should not be given to all children to prevent acute LRTIs. There is evidence for vitamin A supplements to prevent acute LRTIs in children with low serum retinol or those with a poor nutritional status.

Immunostimulants for preventing respiratory tract infection in children

BACKGROUND

Acute respiratory tract infections (ARTIs) are a major cause of childhood morbidity and mortality. Immunostimulants (IS) may reduce the incidence of ARTIs.

OBJECTIVES

To determine the efficacy and safety of IS in preventing ARTIs in children.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2005); MEDLINE (January 1966 to January 2006); and EMBASE (January 1990 to January 2006); PASCAL (up to January 2006); SciSearch (up to January 2006); and IPA (up to January 2006) for reports of trials. Investigators in the field were also contacted. Ongoing studies were searched in the trial registration web site, metaRegister of Controlled Trials.

SELECTION CRITERIA

All comparative trials which enrolled patients less than 18 years of age were included. The intervention of interest was the use of an IS medication administered by any method for preventing ARTIs. Clinical trials using random or quasi-random allocation and comparing IS medication or medications to placebo were included.

DATA COLLECTION AND ANALYSIS

The outcome on ARTIs was analyzed both as the mean number of ARTIs by group and as a percent change in the rate of ARTIs. Meta-analysis was undertaken using a random-effects model and results were presented as weighted mean differences (WMD) with 95% confidence intervals (CI). The trials search, quality assessment and data extraction were undertaken independently by two authors. A funnel plot suggested there may be publication bias in the trials identified.

MAIN RESULTS

Thirty-four placebo controlled trials (3877 participants) provided data in a form suitable for inclusion in the meta-analysis. When compared with placebo, the use of IS was shown to reduce ARTIs measured as the total numbers of ARTIs (WMD -1.27; 95% CI -1.58 to -0.97) and the difference in ARTIs rates (WMD -39.68%; 95% CI -47.27% to -32.09%). The trial quality was generally poor and a high level of statistical heterogeneity was evident. The subgroup analysis of bacterial IS studies produced similar results, with lower heterogeneity. No difference in adverse events was evident between the placebo and IS groups

AUTHORS' CONCLUSIONS

This review showed that IS reduces the incidence of ARTIs in children, by 40% on average. However, due to significant heterogeneity and the poor quality of the trials this positive result should be interpreted with caution. The safety profile of IS appears to be good. Further high-quality trials are needed and we encourage national health authorities to conduct large, multicenter, double-blind, placebo-controlled trials on the role of IS in the prevention of ARTIs.